A. Field of the Invention
This invention relates to the field of wheelchair backs and covers and adjustment mechanisms and cushions for the same. More particularly, the inventors have invented a wheelchair back with width adjustable wings, a wheelchair back with forward and backward angular adjustment, a latch mechanism useful for attaching a wheelchair back to a wheelchair and useful in other environments as well, and a width adjustable wheelchair back cover and padding assembly. Additionally, various of the invented structures have useful application in products other than wheelchairs and the inventors have recognized this and intend to secure protection in fields other than wheelchairs.
B. The Background Art
In the background art, there had been some work done in the area of adjustable and foldable disassemblable wheelchairs. The reader is directed to the following U.S. Patent Nos. for representative examples: U.S. Pat. No. Re. 32,242 issued in the name of Jeffrey P. Minnebraker; U.S. Pat. No. 5,253,888 issued in the name of Paul Frederich; U.S. Pat. No. 5,152,543 issued in the names of Larry A. Sims, Robert W. Reynolds, Raymond P. Lewandowski, and Robert T. McWethy; U.S. Pat. No. 4,989,890 issued in the names of Walter G. Lockard, Herbert J. Hockstra, Allen J. Boris and Douglas M. Nickles; U.S. Pat. No. 4,500,102 issued in the names of Gilbert E. Haury, Nathalal G. Patel, Walter G. Lockard and Thomas R. Wiatrak; U.S. Pat. No. 4,489,955 issued in the name of W. Duane Hamilton; U.S. Pat. No. 4,431,076 issued in the name of Robert C. Simpson; U.S. Pat. No. 3,618,068 issued in the name of Edward M. Greer; and U.S. Pat. No. 2,824,597 issued in the name of Monroe Arnold Lerman, each of which is hereby incorporated by reference. The '242 patent discloses a wheelchair that accommodates patients of different sizes. The '888 patent discloses a wheelchair designed for quick disassembly which provides some adjustment. The '543 patent discloses a composite frame wheelchair that offers some adjustment to the user. The '890 patent discloses a wheelchair that provides both length and width adjustment. The '102 patent discloses a wheelchair that has various adjustment features. The '955 patent discloses a wheelchair with an adjustable center of gravity. The '076 patent discloses a wheelchair that has adjustable arm resets and a self-standing feature. The '068 patent discloses a wheelchair that has an angular adjustable backrest. The '597 patent discloses a width adjustable wheelchair.
Tilting and angle adjustable seat backs are disclosed in the following U.S. Patents: U.S. Pat. No. 2,491,154, issued in the name of Lawrence E. Blazey; U.S. Pat. No. 2,565,867, issued in the name of Carl Ernst Edvard Lundquist; U.S. Pat. No. 3,618,968, issued in the name of Edward M. Greer; U.S. Pat. No. 3,964,786, issued in the name of David Mashuda; U.S. Pat. No. 4,500,102, issued in the names of Gilbert E. Haury, Nathalal G. Patel, Walter G. Lockard and Thomas R. Wiatrak; U.S. Pat. No. 4,592,570, issued in the name of Joe-Massoud Nassiri; U.S. Pat. No. 4,593,929, issued in the name of Ronald H. Williams; U.S. Pat. No. 5,035,467, issued in the names of Peter Axelson, Michael Heinrich, Ann Lasko-Harvill and Michael W. Silverman; U.S. Pat. No. 5,062,677, issued in the names of Eric C. Jay and Michael H. Nordquist; U.S. Pat. No. 5,127,709, issued in the names of Stanley Rubinstein and Terry D. Robuck; U.S. Pat. No. 5,211,446, issued in the names of Eric C. Jay and Michael H. Nordquist; U.S. Pat. No. 5,364,162, issued in the names of Christopher Bar and Calvin L. Guthrie; and U.S. Pat. No. 5,556,168, issued in the names of John C. Dinsmoor, III, Barry Van Everen, Michael W. Johnson and Grant C. Denton.
The '154 patent discloses a seat back for a stenographer's chair which tilts freely to adjust to the user's back. The '867 patent discloses a mechanism for locking the back of a chair into different angular positions relative to the chair seat. The mechanism of the '867 patent includes an elongate guide or slot connected to the seat back, which is clamped between supporting arms with a bolt and a wing nut. The supporting arms, which are connected to the chair seat, each have a non-circular curved slot formed therethrough. The elongate guide or slot provides height adjustability, while the curved slots in the supporting arms impart angular adjustability to the seat back.
The '968 patent discloses a wheelchair having a seat back with angle adjustability. The angle adjustment mechanism of the '968 patent includes upright tubular members which are pivotally connected to the wheelchair frame and a hydraulic actuator. One end of the hydraulic actuator is pivotally connected to the upright tubular member. The other end of the hydraulic actuator is pivotally connected to the wheelchair frame.
The wheelchair seat back of the '786 patent is pivotally mounted to the seat bottom by pins or rivets. Angular motion of the seat back around the mount is governed by a hydraulic actuator. The stationary end of the hydraulic actuator is pivotally connected to the frame of the seat bottom. The piston end of the hydraulic actuator is pivotally connected to a curved bracket that is fixedly attached to the seat back.
In the seat back angular adjustment mechanism of the '102 patent, a hinge connects the lower portion of the seat back to the wheelchair frame. A first attachment mechanism pivotally connects the seat back to the hinge. A second attachment mechanism includes an arcuate slot through which a fastener passes to secure the seat back to the hinge in the desired angular position.
Similarly, the '570 includes a mechanism for adjusting the angle of the seat back relative to the wheelchair frame. That mechanism includes an L-shaped bracket, the horizontal arm of which is fixedly attached to a horizontal member of the wheelchair. The bottom of the seat back pivotally attaches at the corner of the L-shaped bracket with a first fastener. The vertical arm of the bracket includes an arcuate slot, through which a second fastener passes, and which facilitates angular adjustment of the seat back.
The angle adjustment mechanism disclosed in the '929 patent includes a planetary gear arrangement operably interconnected with a knob, such as that used to adjust the seat backs of some automobiles. The adjustment mechanism is located at the base of the seat back frame, and connects the seat back to the side frame.
The '467 patent discloses a seating system wherein the seat back is pivotally attached to the seat bottom. The angle of the seat back disclosed in the '677 patent changes depending upon the position of the seat back along arcuate uprights.
The '709 patent discloses a quick release attachment bracket for a wheelchair seat back. Two J-shaped members that are attached to each side of the seat back engage each of the wheelchair uprights. The quick release brackets are fixedly mounted to the uprights such that they are aligned with the J-shaped members. The quick release brackets force the J-shaped members against the uprights, forcing the J-shaped members against the uprights. The horizontal position of each bracket may be adjusted relative to the seat back to provide angular adjustment of the seat back relative to the upright.
The '446 patent discloses angular adjustment of a seat back which is governed by the placement of the seat back along arcuate uprights. The '162 patent discloses a backrest assembly for a wheelchair wherein two U-shaped outriggers are pivotally attached to both of a wheelchair's uprights. The outriggers are positioned across the wheelchair near the upper and lower portions of the seat back such that the back rests upon the transverse portion of the outriggers. Clamps on the seat back engage the outriggers in several positions. The angle of the seat back relative to the uprights is adjusted by rotation of the outriggers within the clamp.
In the '168 patent, a wheelchair seat back is disclosed that is fastened to spaced apart support posts by use of hook and mounting units. The hook and mounting units of the '168 patent are located at upper and lower positions on each side of the seat back. The hooks engage a wheelchair upright. Slots formed through the hooks permit adjustment of the positions of both the upper and lower hooks relative to the seat back, facilitating angular adjustment of the seat back relative to the wheelchair. However, the angular adjustment mechanism of the '168 patent does not allow for pivotal adjustment of the seat back, and thus requires some movement of at least one of the upper or lower brackets relative to the upright.
In a PCT patent application which was assigned International Publication Number WO 92/14387 in the name of inventors Eric C. Jay, John A. Dyer and John C. Dinsmoor, which is hereby incorporated by reference, a wheelchair back which is adjustably affixed to a rod is disclosed.
U.S. Pat. No. 1,734,179, issued in the name of P. W. Olson, U.S. Pat. No. 3,379,450 issued in the name of E. Jones et al., U.S. Pat. No. 3,704,910 issued in the name of Walter F. Wilcott, U.S. Pat. No. 4,375,295 issued in the name of Frank Volin, U.S. Pat. No. 4,565,385 issued in the name of Marvin A. Morford, and U.S. Pat. No. 4,746,168 issued in the name of Roberto Bacesco, each of which is hereby incorporated by reference, disclose various wheelchair and seating-related apparatus, including adjustability thereof.
In a catalog entitled "OTTO BOCK Orthopedic Industry Wheelchair Seating Accessories and Hardware Catalogue 1992", which is hereby incorporated by reference, various back cushions, backshells and attachment mechanisms for them are disclosed, as well as other wheelchair-related products.
For more general background related to wheelchair back and seat mechanisms, the reader is directed to U.S. Pat. No. 5,108,202 issued in the name of Kenneth B. Smith, U.S. Pat. No. 4,884,841 issued in the name of Robert E. Holley and U.S. Pat. No. 4,054,319 issued in the name of Robert K. Fogg, Jr. and Christopher P. Staehli, each of which is hereby incorporated by reference. The '202 patent discloses a structure for raising a patient seated in the wheelchair to a standing position. The '841 patent discloses a mechanism for assisting patient into and from a seated position. The '319 patent discloses a wheelchair that can accommodate a patient in a seated position, in a standing position, or in a variety of positions between sitting and standing.
For information related to adjustability devices and supports, including those related to wheelchairs and wheelchair seating, the reader is directed to the following U.S. Patents: U.S. Pat. No. 3,790,115 issued in the name of Abraham J. Schulman; U.S. Pat. No. 4,076,195 issued in the name of Douglas Lester Uhler; U.S. Pat. No. 4,687,165 issued in the name of Robert S. Blackburn; U.S. Pat. No. 5,149,173 issued in the name of Eric C. Jay; U.S. Pat. No. 5,352,023 issued in the names of Eric C. Jay and John C. Dinsmoor, III; and U.S. Pat. No. 5,364,162 issued in the names of Christopher Bar and Calvin Guthrie, each of which is hereby incorporated by reference. The '115 patent discloses an expandable support with a telescoping feature. The '195 patent discloses an adjustable mounting assembly. The '165 patent discloses an adapter plate assembly for adjustable mounting of objects. The '173 patent discloses wheelchair seat backs. The '023 patent discloses wheelchair seat and back assemblies.
For information related to frame structures from which wheelchair components might be made, the reader is directed to U.S. Pat. No. 5,464,240 issued in the names of Alexander J. Robinson and Christopher O. Paragas, U.S. Pat. No. 5,011,172 issued in the names of August T. Bellanca and August T. Bellanca, Jr., U.S. Pat. No. 4,550,727 issued in the name of Peter Resele, U.S. Pat. No. 4,548,422 issued in the names of Diaz Michel and Loeillet Christian, and U.S. Pat. No. 3,533,643 issued in the name of Ryoichi Yamada, each of which is hereby incorporated by reference. The reader is also directed to Italian patent no. 448,310 (Jul. 11, 1949), French patent no. 895,046 (Jan. 12, 1945) and Great Britain patent no. 19,193 (Nov. 16, 1895), each of which is hereby incorporated by reference. The '240 patent discloses a two piece hollow shell frame made from fiber-reinforced plastic which uses tangs and devises and protrusions and receptacles for added strength. The '172 patent discloses various lightweight frame structures. The '927 patent discloses a two-part shell frame for two-wheeled vehicles. The '422 patent discloses a bicycle frame made from two joined shell halves. The '643 patent discloses a bicycle frame assembly. The Italian patent discloses cross sections of various frames or tubing. The French patent discloses a bicycle frame including its cross-sectional view. The British patent discloses three different cross sections of a bicycle frame.
Applicants are aware of various pieces of art in the area of cushioning. For general information regarding cushioning devices in the background art, the reader is directed to Great Britain Patent No. 1,261,475 (Jan. 2, 1972) and the following U.S. Patents: U.S. Pat. No. 1,228,783, issued in the name of G. E. Kerivan; U.S. Pat. No. 2,491,557 issued in the name of G. L. Goolsbee; U.S. Pat. No. 2,655,369 issued in the name of L. C. Musilli; U.S. Pat. No. 2,672,183 issued in the name of A. E. Forsyth; U.S. Pat. No. 2,814,053 issued in the name of J. G. Sevcik; U.S. Pat. No. 3,459,179 issued in the name of I. Olesen; U.S. Pat. No. 3,605,145 issued in the name of R. H. Graebe; U.S. Pat. No. 3,801,420 issued in the name of Ann Anderson; U.S. Pat. No. 3,893,198 issued in the name of E. Allan Blair; U.S. Pat. No. 3,968,530 issued in the name of Reginald Dyson; U.S. Pat. No. 4,163,297 issued in the name of Otto W. Neumark; U.S. Pat. No. 4,247,963 issued in the name of Lakshmi Reddi; U.S. Pat. No. 4,274,169 issued in the name of Natalie C. Sandiford; U.S. Pat. No. 4,483,029 issued in the name of Patrick R. D. Paul; U.S. Pat. No. 4,485,505 issued in the name of Patrick R. D. Paul; U.S. Pat. No. 4,498,205 issued in the name of Kazuhiko Hino; U.S. Pat. No. 4,572,174 issued in the names of Kaeriel Elleader and Mille Stand; U.S. Pat. No. 4,588,229 issued in the name of Eric C. Jay; U.S. Pat. No. 4,628,557 issued in the name of Michael E. Murphy; U.S. Pat. No. 4,660,238 issued in the name of Eric C. Jay; U.S. Pat. No. 4,698,864 issued in the name of Robert H. Graebe; U.S. Pat. No. 4,713,854 issued in the name of Robert H. Graebe; U.S. Pat. No. 4,726,624 issued in the name of Eric C. Jay; U.S. Pat. No. 4,728,551 issued in the name of Eric C. Jay; U.S. Pat. No. 4,737,998 issued in the name of Arthur K. Johnson, Sr.; U.S. Pat. No. 4,842,330 issued in the name of Eric C. Jay; U.S. Pat. No. 5,018,790 issued in the name of Eric C. Jay; U.S. Pat. No. 5,052,068 issued in the name of Robert H. Graebe; U.S. Pat. No. 5,111,544 issued in the name of Robert H. Graebe; U.S. Pat. No. 5,152,023 issued in the name of Robert H. Graebe; U.S. Pat. No. 5,163,196 issued in the names of Robert H. Graebe and Winfield R. Matsler; U.S. Pat. No. 5,201,780 issued in the names of John C. Dinsmoor, III, Grant C. Seaon, Eric C. Jay and Richard R. Runkles; U.S. Pat. No. 5,282,286 issued in the name of Michael MacLeish; U.S. Pat. No. 5,360,653 issued in the name of Robert E. Ackley; U.S. Pat. No. 5,369,828 issued in the name of Robert H. Graebe; U.S. Pat. No. 5,421,874 issued in the name of Tony M. Pearce; and U.S. Pat. No. 5,429,852 issued in the name of Raymond Quinn, each of which is hereby incorporated by reference. The British patent discloses a mattress with air or water inflatable members. The '783 patent discloses a pneumatic mattress. The '557 patent discloses a mattress having multiple air cells. The '369 patent discloses a shock absorbing device that includes adjacent, cooperating deformable chambers containing a fluid medium. The '183 patent discloses a seat cushion that has a plurality of inflatable cylindrical elements. The '053 patent discloses an inflatable mattress. The '179 patent discloses a supporting pad filled with expanded polystyrene beads. The '145 patent discloses a body support having numerous pliant, outwardly extending air cells. The '420 patent discloses a quilted bedspread. The '198 patent discloses a foam mattress. The '530 patent discloses a pad containing a mixture of a viscous gel fluid and silica and re-expanded polystyrene beads. The '297 patent discloses a mattress that has multiple pillows partially filled with polystyrene beads. The '963 patent discloses a two-sheet liquid support device. The '169 patent discloses a stitched bed covering. The '029 patent discloses a fluidized supporting apparatus containing granular material. The '505 patent discloses an inflatable mattress with resilient support cells. The '205 patent discloses a medical bed containing fluidized particle media. The '174 patent discloses a low friction bed pad. The '229 patent discloses a seat cushion with a fluid filling material. The '557 patent discloses a mattress with removable inserts. The '238 patent discloses a hemorrhoid seat cushion partially filled with a fluid. The '864 patent discloses a cellular cushion having flexible hollow cells. The '854 patent discloses a cushion formed from strips of resilient foam. The '624 patent discloses a seat cushion containing a fluid filling material. The '551 patent discloses flowable pressure compensating fitting materials. The '998 patent discloses a waterbed mattress with free-standing cells arranged in a honeycomb pattern. The '330 patent discloses a seat cushion that has a foam base and a fluid portion. The '790 patent discloses a seat cushion which can be customized by the user. The '068 patent discloses a seat cushion with inflatable, upwardly projecting cells. The '544 patent discloses cover for a cushion. The '023 patent discloses a cushion having flexible cells formed from an elastomeric material and containing a gas. The '196 patent discloses an inflatable cushion with zoned cells. The '780 patent discloses a multilayer mattress pad which includes a fluid bladder. The '286 patent discloses a cushion which has fluid floatation characteristics. The '653 patent discloses a foam pad. The '828 patent discloses a cushion having pyramidal air cells. The '874 patent discloses a cushioning material that includes lightly lubricated microspheres. The '852 patent discloses a chair pad that includes foam among its various layers.
Each of the above references is hereby incorporated by reference in its entirety.
What is needed is a width-adjustable rigid seat back for a wheelchair. In addition, a light weight seat back is desired. A mechanism is needed which provides improved angular adjustment of a wheelchair seat back or other device in the fore and aft directions. Adjustability to several discrete angular positions is also needed. A seat back attachment mechanism is needed which is easy to use and which facilitates the ready removability of a seat back from, and ready and secure replacement of a seat back upon a wheelchair. Further, a cushion and cover for a width-adjustable seat back is needed.